Numerical Simulation of GaN Growth in a MOCVD Process

2011 ◽  
Author(s):  
Jiandong Meng ◽  
Yogesh Jaluria
Keyword(s):  
Growth Rate ◽  
Film Growth ◽  
Chemical Vapor ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Reactor Performance ◽  
Chemical Mechanisms ◽  
Mocvd Reactor ◽  
Reactor Operating ◽  
Gan Film

This paper describes a model for the growth of gallium nitride in a vertical impinging metalorganic chemical vapor deposition (MOCVD) reactor. With trimethylgallium (TMGa) and ammonia (NH3) carried by hydrogen (H2) as precursors, the flow, temperature and concentration profiles are predicted by numerical modeling, which is performed using a commercial CFD software package CFD-ACE+. The growth rate is predicted based on detailed reaction mechanisms given in the literature, and related studies are carried out to verify the reliability and adaptability of the chosen chemical kinetics. A detailed mathematical model is developed first, and the complete chemical mechanisms are introduced. Then, the dependence of the growth rate and uniformity of the deposited layers on operating conditions, such as reactor operating pressure, susceptor temperature, inlet velocity and concentration of the precursors, is investigated to gain greater insight into the reactor performance and characteristics. Based on the simulation results, discussion is presented in this paper to offer the possibility of better control of the GaN film growth process, and to ultimately lead to an optimization of the process, with respect to production rate and film quality.

Numerical Simulation of GaN Growth in a Metalorganic Chemical Vapor Deposition Process

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Jiandong Meng ◽  
Yogesh Jaluria
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Reactor Performance ◽  
Metalorganic Chemical

A detailed mathematical model for the growth of gallium nitride in a vertical impinging metalorganic chemical vapor deposition (MOCVD) reactor is developed first, and the complete chemical mechanisms are introduced. Then, one validation study is conducted to ensure its accuracy. After that, the flow, temperature and concentration profiles are predicted by numerical modeling. The dependence of the growth rate and uniformity of the deposited layers on operating conditions, such as reactor operating pressure, susceptor temperature, inlet velocity and concentration ratio of the precursors, is investigated to gain greater insight into the reactor performance and characteristics. Based on the simulation results, discussion is presented in this paper to offer the possibility of better control of the GaN film growth process and to ultimately lead to an optimization of the process, with respect to production rate and film quality.

Numerical Simulation of the Effection of Inlet Velocity in GaN Growth by MOCVD

2014 ◽  
Vol 556-562 ◽  
pp. 4155-4158
Author(s):  
Dong Sheng Peng ◽  
Zhi Gang Chen ◽  
Cong Cong Tan
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Reactor Performance ◽  
Inlet Velocity ◽  
Mocvd Reactor ◽  
Simulation Results ◽  
Gan Film ◽  
Insight Into

A mathematical model for the growth of gallium nitride in a vertical impinging metalorganic chemical vapor deposition (MOCVD) reactor is developed. The dependence of the GaN film and the uniformity of the deposited layers on the inlet velocity is investigated to gain greater insight into the reactor performance and characteristics. Based on the simulation results, discussion is presented in this paper to offer the possibility of better control of the GaN film growth process and to ultimately lead to an optimization of the process.

Fabrication of GaN Films in a Chemical Vapor Deposition Reactor

2013 ◽  
Author(s):  
J. Meng ◽  
Y. Jaluria ◽  
S. Wong
Keyword(s):  
Growth Rate ◽  
Film Growth ◽  
Numerical Study ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
Transport Processes ◽  
Operating Conditions ◽  
Fluid Loss ◽  
Flow Recirculation

A three-dimensional numerical study has been carried out on the rotating disk GaN MOCVD process, and it is also coupled with an experimental study on the flow and thermal transport processes in the system. An impingement type reactor, with a rotating base, is considered. The dependence of the thin film growth rate and uniformity on operating conditions such as inflow velocity, rotational speed, and susceptor temperature are investigated in detail. Similarly, the effect of the geometry and configuration of the reactor are studied. The study also considers the effect of thermal and solutal buoyancy on the resulting flow. The flow and the associated transport processes are discussed in detail on the basis of the results obtained to suggest approaches to improve the uniformity of the film, minimize fluid loss and reduce flow recirculation that could affect growth rate and uniformity.

Novel Design of MOCVD Reactor with Three Radial Inward Flows for Epitaxial Growth of GaN Thin Films

2011 ◽  
Vol 308-310 ◽  
pp. 1037-1040
Author(s):  
Liao Qiao Yang ◽  
Jian Zheng Hu ◽  
Zun Miao Chen ◽  
Jian Hua Zhang ◽  
Alan G. Li
Keyword(s):  
Gas Flow ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Operating Pressure ◽  
Axisymmetric Mode ◽  
Mocvd Reactor ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
D Model

In this paper, a novel super large metal organic chemical vapor deposition (MOCVD) reactor with three inlets located on the periphery of reactor was proposed and numerical evaluation of growth conditions for GaN thin film was characterized. In this design, the converging effects of gas flow in the radial direction could counterbalance the dissipation of metal organics source. CFD was used for the mathematical solution of the fluid flow, temperature and concentration fields. A 2-D model utilizing axisymmetric mode to simulate the gas flow in a MOCVD has been developed. The growth of GaN films using TMGa as a precursor, hydrogen as carrier gas was investigated. The effects of flow rates, mass fraction of various species, operating pressure, and gravity were analyzed and discussed, respectively. The numerical simulation results show all the fields distributions were in an acceptable range.

On the optimization of a dc arcjet diamond chemical vapor deposition reactor

1996 ◽  
Vol 11 (3) ◽  
pp. 694-702 ◽  
Author(s):  
S. W. Reeve ◽  
W. A. Weimer ◽  
D. S. Dandy
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Methyl Radical ◽  
Chemical Kinetic Model ◽  
Model Calculations ◽  
Chemical Vapor Deposition Reactor

Based on results from chemical kinetic model calculations, a method to improve diamond film growth in a dc arcjet chemical vapor deposition reactor has been developed. Introducing the carbon source gas (CH4) into an Ar/H2 plasma in close proximity to the substrate produced diamond films exhibiting simultaneous improvements in quality and mass deposition rates. These improvements result from a reduced residence time of the methane in the plasma which inhibits the hydrocarbon chemistry in the gas from proceeding significantly beyond methyl radical production prior to encountering the substrate. Improvements in growth rate were modest, increasing by only a factor of two. Optical emission actinometry measurements indicate that the flux of atomic hydrogen across the stagnation layer to the substrate is mass diffusion limited. Since diamond growth depends upon the flux of atomic H to the substrate, these results suggest that under the conditions examined here, a low atomic H flux to the substrate poses an upper limit on the attainable diamond growth rate.

Deposition of YSZ Thin Films by Liquid Fuel Combustion Chemical Vapor Deposition

2002 ◽  
Author(s):  
Zhigang Xu ◽  
Jag Sankar ◽  
Qiuming Wei ◽  
Jim Lua ◽  
Sergey Yamolenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Substrate Temperature ◽  
Vapor Deposition ◽  
Liquid Fuel ◽  
Film Growth ◽  
Early Stage ◽  
Chemical Vapor ◽  
Nucleation Density

Thin film of YSZ electrolyte is highly desired to reduce the electrical resistance in SOFCs. YSZ thin Films have been successfully produced using liquid fuel combustion chemical vapor deposition (CCVD) technique. Nucleation of the YSZ particles were investigated based on two processing parameters, i.e., substrate temperature and total-metal-concentration in the liquid fuel. An optimum substrate temperature was found for highest the nucleation density. The nucleation density was increased with the total-metal-concentration. Microstructure evolution of the YSZ particles in the early stage in film growth was also studied. It was found that the particle growth rate was linear with processing time, and the particle orientation was varying with the time in the early stage of the film processing. To enhance the film growth rate, the effect of thermophoresis was studied. By increase the temperature gradient towards substrate, the effect of thermophoresis was enhanced and the film growth is also increased.

Hydrogen effect on near-atmospheric nitrogen plasma assisted chemical vapor deposition of GaN film growth

2009 ◽  
Vol 105 (6) ◽  
pp. 066106 ◽  
Author(s):  
T. Nagata ◽  
M. Haemori ◽  
Y. Sakuma ◽  
T. Chikyow ◽  
J. Anzai ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Nitrogen Plasma ◽  
Hydrogen Effect ◽  
Atmospheric Nitrogen ◽  
Gan Film

Evaluation of the Accuracy of Selected Syngas Chemical Mechanisms

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Fahad M. Alzahrani ◽  
Yinka S. Sanusi ◽  
Konstantina Vogiatzaki ◽  
Ahmed F. Ghoniem ◽  
Mohamed A. Habib ◽  
...  
Keyword(s):  
Equivalence Ratio ◽  
Laminar Flame ◽  
Computational Cost ◽  
Operating Conditions ◽  
Average Error ◽  
Operating Pressure ◽  
Chemical Mechanisms ◽  
Flame Thickness ◽  
Reduced Mechanism ◽  
Significant Difference

The implementation of reduced syngas combustion mechanisms in numerical combustion studies has become inevitable in order to reduce the computational cost without compromising the predictions' accuracy. In this regard, the present study evaluates the predictive capabilities of selected detailed, reduced, and global syngas chemical mechanisms by comparing the numerical results with experimental laminar flame speed (LFS) values of lean premixed (LPM) syngas flames. The comparisons are carried out at varying equivalence ratios, syngas compositions, operating pressures, and preheat temperatures to represent a range of operating conditions of modern fuel flexible combustion systems. NOx emissions predicted by the detailed mechanism, GRI-Mech. 3.0, are also used to study the accuracy of the selected mechanisms under these operating conditions. Moreover, the selected mechanisms' accuracy in predicting the laminar flame thickness (LFT), species concentrations of the reactants, and OH profiles at different equivalence ratios and syngas compositions are investigated as well. The LFS is generally observed to increase with increasing equivalence ratio, hydrogen content in the syngas, and preheat temperature, while it is decreased with increasing operating pressure. This trend is followed by all mechanisms understudy. The global mechanisms of Watanabe–Otaka and Jones–Lindstedt for syngas are consistently observed to over-predict and under-predict the LFS up to an average of 60% and 80%, respectively. The reduced mechanism of Slavinskaya has an average error of less than 20%, which is comparable to the average error of the GRI-Mech. 3.0. It however over-predicts the flame thickness by up to 30% when compared to GRI-Mech. 3.0. The NO prediction by Li mechanism and the reduced mechanisms are observed to be within 10% prediction range of the GRI-Mech. 3.0 at intermediate equivalence ratio (φ=0.74) up to stoichiometry. Moving toward more lean conditions, there is significant difference between the GRI-Mech. 3.0 NO prediction and those of the reduced mechanisms due to relative importance of the prompt NOx at lower temperature compared to thermal NOx that is only accounted for by the GRI-Mech. 3.0.

Semiconductor Thin Films Grown by Laser Photolysis

1982 ◽  
Vol 17 ◽  
Author(s):  
J.G. Eden ◽  
J.E. Greene ◽  
J.F. Osmundsen ◽  
D. Lubben ◽  
C.C. Abele ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Vapor Deposition ◽  
Film Growth ◽  
Single Photon ◽  
Chemical Vapor ◽  
Intensity Dependence ◽  
Grain Sizes ◽  
Semiconductor Thin Films ◽  
Si Films

ABSTRACTThin (< 1.2 μpm) Ge and Si films have been grown with rates up to 3.6 μm/hr by laser-induced chemical vapor deposition (LCVD) on a variety of substrates. Germanium films grown on amorphous SiO2 (quartz) by photodissociating GeH4 in He at 248 nm (KrF laser) exhibit grain sizes of 0.3 – 0.5 μm that increase only slightly up to the pryolytic threshold for GeH4 (280°C). On (100) NaCl, however, Ge films grown at a substrate temperature of 120°C are expitaxial. The activation energy for the LCVD growth of Ge films (from GeH4) on SiO2 is measured to be 85 ± 20 meV which suggests that germanium is arriving at the substrate in atomic form. The wavelength and intensity dependence of the initial film growth rate supports the conclusion that this process is photolytic and is initiated by the absorption of a single photon.

Effects of thermal contact resistance on film growth rate in a horizontal MOCVD reactor

2005 ◽  
Vol 19 (6) ◽  
pp. 1338-1346 ◽  
Author(s):  
Ik-Tae Im ◽  
Nag Jung Choi ◽  
Masakazu Sugiyama ◽  
Yoshiyaki Nakano ◽  
Yukihiro Shimogaki ◽  
...  
Keyword(s):  
Growth Rate ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Film Growth ◽  
Thermal Contact ◽  
Film Growth Rate ◽  
Mocvd Reactor
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